diff --git a/src/lib/db/quotaPools.ts b/src/lib/db/quotaPools.ts
index 8f72551dea..c2e8b75bc3 100644
--- a/src/lib/db/quotaPools.ts
+++ b/src/lib/db/quotaPools.ts
@@ -370,6 +370,14 @@ export function deletePool(id: string): boolean {
   const database = getDb();
   const doDelete = database.transaction(() => {
     database.prepare("DELETE FROM quota_pool_connections WHERE pool_id = ?").run(id);
+    // Prune this pool id from every key's allowed_quotas JSON array.
+    database.prepare(
+      `UPDATE api_keys SET allowed_quotas = COALESCE(
+         (SELECT json_group_array(value) FROM json_each(api_keys.allowed_quotas) WHERE value != ?),
+         '[]')
+       WHERE allowed_quotas IS NOT NULL AND allowed_quotas != '[]'
+         AND EXISTS (SELECT 1 FROM json_each(api_keys.allowed_quotas) WHERE value = ?)`
+    ).run(id, id);
     return database.prepare("DELETE FROM quota_pools WHERE id = ?").run(id);
   });
   const result = doDelete();
diff --git a/tests/unit/quota-pool-delete-prune.test.ts b/tests/unit/quota-pool-delete-prune.test.ts
new file mode 100644
index 0000000000..15f47a57d3
--- /dev/null
+++ b/tests/unit/quota-pool-delete-prune.test.ts
@@ -0,0 +1,194 @@
+/**
+ * tests/unit/quota-pool-delete-prune.test.ts
+ *
+ * Fix: deletePool should prune its id from every api_key's allowed_quotas JSON array.
+ *
+ * Coverage:
+ * 1. Create a pool, assign it to a key's allowed_quotas → deletePool → key's
+ *    allowed_quotas no longer contains that pool id.
+ * 2. Unrelated pool ids in allowed_quotas are untouched.
+ * 3. Key whose allowed_quotas doesn't contain the deleted pool id → unchanged.
+ * 4. Key with empty allowed_quotas stays empty after delete.
+ * 5. Multiple keys all pruned simultaneously.
+ * 6. deletePool still returns true/false correctly.
+ * 7. Pool row and allocation rows are gone after delete (regression guard).
+ */
+
+import test from "node:test";
+import assert from "node:assert/strict";
+import fs from "node:fs";
+import os from "node:os";
+import path from "node:path";
+
+// ── DB harness (same pattern as quota-exclusivity-reconcile.test.ts) ─────────
+const TEST_DATA_DIR = fs.mkdtempSync(path.join(os.tmpdir(), "omniroute-pool-delete-prune-"));
+process.env.DATA_DIR = TEST_DATA_DIR;
+process.env.API_KEY_SECRET =
+  process.env.API_KEY_SECRET || "delete-prune-test-secret-32chars!!";
+
+const core = await import("../../src/lib/db/core.ts");
+const poolsDb = await import("../../src/lib/db/quotaPools.ts");
+const apiKeysDb = await import("../../src/lib/db/apiKeys.ts");
+
+async function resetStorage() {
+  core.resetDbInstance();
+  apiKeysDb.resetApiKeyState();
+  for (let attempt = 0; attempt < 10; attempt++) {
+    try {
+      if (fs.existsSync(TEST_DATA_DIR)) {
+        fs.rmSync(TEST_DATA_DIR, { recursive: true, force: true });
+      }
+      break;
+    } catch (err: any) {
+      if ((err?.code === "EBUSY" || err?.code === "EPERM") && attempt < 9) {
+        await new Promise((resolve) => setTimeout(resolve, 50 * (attempt + 1)));
+      } else {
+        throw err;
+      }
+    }
+  }
+  fs.mkdirSync(TEST_DATA_DIR, { recursive: true });
+}
+
+test.beforeEach(async () => {
+  await resetStorage();
+});
+
+test.after(async () => {
+  core.resetDbInstance();
+  fs.rmSync(TEST_DATA_DIR, { recursive: true, force: true });
+});
+
+// ── Helper: get allowed_quotas for a key by id from DB ───────────────────────
+function getAllowedQuotasById(keyId: string): string[] {
+  const db = core.getDbInstance();
+  const row = (db as any)
+    .prepare("SELECT allowed_quotas FROM api_keys WHERE id = ?")
+    .get(keyId) as { allowed_quotas: string } | undefined;
+  if (!row) return [];
+  try {
+    const parsed = JSON.parse(row.allowed_quotas ?? "[]");
+    return Array.isArray(parsed) ? parsed : [];
+  } catch {
+    return [];
+  }
+}
+
+// ── 1. Basic prune: deletePool removes pool id from key's allowed_quotas ──────
+
+test("deletePool prunes its id from api_key allowed_quotas", async () => {
+  const pool = poolsDb.createPool({ connectionId: "conn-prune-1", name: "Prune Pool 1" });
+  const keyObj = await apiKeysDb.createApiKey("Prune Key 1", "machine-prune-1");
+  await apiKeysDb.updateApiKeyPermissions(keyObj.id, { allowedQuotas: [pool.id] });
+
+  // Sanity: pool id is there before delete
+  const before = getAllowedQuotasById(keyObj.id);
+  assert.ok(before.includes(pool.id), `pool.id should be in allowed_quotas before delete`);
+
+  poolsDb.deletePool(pool.id);
+
+  const after = getAllowedQuotasById(keyObj.id);
+  assert.ok(!after.includes(pool.id), `pool.id should NOT be in allowed_quotas after delete`);
+});
+
+// ── 2. Unrelated pool ids are preserved ───────────────────────────────────────
+
+test("deletePool preserves unrelated pool ids in allowed_quotas", async () => {
+  const poolToDelete = poolsDb.createPool({ connectionId: "conn-prune-2a", name: "Delete Me" });
+  const otherPool = poolsDb.createPool({ connectionId: "conn-prune-2b", name: "Keep Me" });
+  const unrelatedId = "unrelated-pool-id-xyz";
+
+  const keyObj = await apiKeysDb.createApiKey("Prune Key 2", "machine-prune-2");
+  await apiKeysDb.updateApiKeyPermissions(keyObj.id, {
+    allowedQuotas: [poolToDelete.id, otherPool.id, unrelatedId],
+  });
+
+  poolsDb.deletePool(poolToDelete.id);
+
+  const after = getAllowedQuotasById(keyObj.id);
+  assert.ok(!after.includes(poolToDelete.id), "deleted pool id should be removed");
+  assert.ok(after.includes(otherPool.id), "other pool id should remain");
+  assert.ok(after.includes(unrelatedId), "unrelated id should remain");
+});
+
+// ── 3. Keys without the pool id are unchanged ─────────────────────────────────
+
+test("deletePool does not modify keys that don't reference the deleted pool", async () => {
+  const poolToDelete = poolsDb.createPool({ connectionId: "conn-prune-3a", name: "Target" });
+  const otherPool = poolsDb.createPool({ connectionId: "conn-prune-3b", name: "Other" });
+
+  const keyObj = await apiKeysDb.createApiKey("Prune Key 3", "machine-prune-3");
+  // This key only references otherPool, not poolToDelete
+  await apiKeysDb.updateApiKeyPermissions(keyObj.id, { allowedQuotas: [otherPool.id] });
+
+  poolsDb.deletePool(poolToDelete.id);
+
+  const after = getAllowedQuotasById(keyObj.id);
+  assert.deepEqual(after, [otherPool.id], "key referencing only other pool should be unchanged");
+});
+
+// ── 4. Key with empty allowed_quotas remains empty ───────────────────────────
+
+test("deletePool: key with empty allowed_quotas stays empty", async () => {
+  const pool = poolsDb.createPool({ connectionId: "conn-prune-4", name: "Empty Test" });
+  const keyObj = await apiKeysDb.createApiKey("Prune Key 4", "machine-prune-4");
+  // Don't set allowedQuotas — default is []
+
+  poolsDb.deletePool(pool.id);
+
+  const after = getAllowedQuotasById(keyObj.id);
+  assert.deepEqual(after, [], "empty allowed_quotas should remain empty after delete");
+});
+
+// ── 5. Multiple keys: all pruned simultaneously ───────────────────────────────
+
+test("deletePool prunes pool id from ALL keys that reference it", async () => {
+  const pool = poolsDb.createPool({ connectionId: "conn-prune-5", name: "Multi Key Pool" });
+
+  const keys = await Promise.all([
+    apiKeysDb.createApiKey("Prune Multi 1", "machine-pm-1"),
+    apiKeysDb.createApiKey("Prune Multi 2", "machine-pm-2"),
+    apiKeysDb.createApiKey("Prune Multi 3", "machine-pm-3"),
+  ]);
+
+  const otherPoolId = "other-pool-id-static";
+  for (const k of keys) {
+    await apiKeysDb.updateApiKeyPermissions(k.id, { allowedQuotas: [pool.id, otherPoolId] });
+  }
+
+  poolsDb.deletePool(pool.id);
+
+  for (const k of keys) {
+    const after = getAllowedQuotasById(k.id);
+    assert.ok(!after.includes(pool.id), `${k.name}: pool.id should be pruned`);
+    assert.ok(after.includes(otherPoolId), `${k.name}: other-pool-id should remain`);
+  }
+});
+
+// ── 6. deletePool still returns true/false correctly ─────────────────────────
+
+test("deletePool returns true for existing pool, false for non-existent", () => {
+  const pool = poolsDb.createPool({ connectionId: "conn-ret-1", name: "Return Test" });
+  assert.equal(poolsDb.deletePool(pool.id), true, "should return true for existing pool");
+  assert.equal(poolsDb.deletePool(pool.id), false, "should return false for already-deleted pool");
+  assert.equal(poolsDb.deletePool("nonexistent-id"), false, "should return false for unknown id");
+});
+
+// ── 7. Pool row and allocation rows are gone after delete (regression guard) ──
+
+test("deletePool removes pool and allocation rows from DB", () => {
+  const pool = poolsDb.createPool({
+    connectionId: "conn-reg-1",
+    name: "Regression Pool",
+    allocations: [{ apiKeyId: "key-reg-1", weight: 50, policy: "hard" }],
+  });
+
+  poolsDb.deletePool(pool.id);
+
+  assert.equal(poolsDb.getPool(pool.id), null, "getPool should return null after delete");
+  const allPools = poolsDb.listPools();
+  assert.ok(
+    !allPools.some((p) => p.id === pool.id),
+    "listPools should not contain the deleted pool"
+  );
+});